With global superpowers engaged in an increasingly hostile arms race, Superman (Christopher Reeve) leads a crusade to rid the world of nuclear weapons. But Lex Luthor (Gene Hackman), recently sprung from jail, is declaring war on the Man of Steel and his quest to save the planet. Using a strand of Superman's hair, Luthor synthesizes a powerful ally known as Nuclear Man (Mark Pillow) and ignites an epic battle spanning Earth and space.